The present invention relates to a contact lens cleaning and storage composition which is suitable for storing a contact lens as well as cleaning it.
Various contact lenses have hitherto been employed, and they are classified roughly into a water-absorptive contact lens and a water-nonabsorptive contact lens. Representative water-nonabsorptive contact lenses are polymethyl methacrylate contact lenses and silicone rubber contact lenses. Further, in recent years, contact lenses made of cellulose acetate butyrate and contact lenses made of a copolymer of a polysiloxanyl alkyl methacrylate and methyl methacrylate or the like are known as water-nonabsorptive contact lenses having an oxygen permeability. These contact lenses, particularly water-nonabsorptive contact lenses, are contaminated when worn on the eyes, by sticking of secretions in the eyes such as proteins and lipids to the lens surface. For this reason, the contact lenses taken off from the eyes must be promptly cleaned to remove contaminants such as proteins and lipids sticking to the lens surface. Wearing of insufficiently cleaned contact lenses results in a great cause for uncomfortable symptoms such as foggy sight, pain and ocular injection, so the wearing must be stopped.
Cleaning of contact lenses has been conducted generally by a method in which a solution containing an ether of a higher alcohol in a physiological saline water is employed as a cleaning solution and the lenses are washed and rubbed with fingers. The cleaned contact lenses are rinsed with a tap water or a physiological saline solution and then stored by soaking them in a physiological saline solution or the like. The storage of the contact lens in a soaking solution is necessary for water-absorptive contact lenses to maintain them in a hydrated state. Even in case of water-nonabsorptive contact lenses, it is desirable to store them in a soaking solution in maintaining the lens surface hydrophilic and in storing cleanly and sanitarily.
In general, it is necessary to employ separately a cleaning solution and a storing solution for the cleaning and storage of contact lenses. The contact lens cleaning solution is required to have an excellent cleaning ability, since the object of its use is cleaning of contact lenses. The contact lens storing solution is desirable to be high in safety and low in irritation to the eye even in case of using it for water-nonabsorptive contact lenses, to say nothing of water-absorptive contact lenses, in that the contact lenses soaked for storage are taken out from the storing solution and worn on the eyes. The use of separate cleaning and storage solutions is very inconvenient to the user, since it requires troublesome procedures and also there is a case where the user stores the contact lenses in a cleaning solution by mistake.
The object of the present invention is to provide a cleaning and storage composition for contact lenses.
A further object of the invention is to provide a cleaning and storage composition for contact lenses, especially for water-nonabsorptive contact lenses, which has both cleaning and storing functions.
A still further object of the invention is to provide a cleaning and storage solution which is usable as a cleaning solution with a high cleaning ability and is also usable as a storage solution in safety and without giving irritation to the eyes.